The “Jason Bay plays against favorable matchups platoon” officially began for the Mets Wednesday night though, according to manager Terry Collins, the high-priced, low-return outfielder eventually can work his way back as an everyday player.

For the short term, however, two left-handed hitters, Jordany Valdespin and Mike Baxter, will try to keep the platoon intact.

Collins started Valdespin in left field and Baxter in right field against Miami last night as the Mets lost their ninth straight at home, 13-0. Collins said he believes Bay, who grounded out as a pinch hitter to end the sixth inning, can escape the seems-like-forever funk that prompted his benching against righties and made him as popular with fans as Oliver Perez.

“What he and I talked about is we’re going to certainly pick our spots for him to play. Hopefully build up the confidence where he’s … swinging the bat good,” Collins said. “That leads to more confidence. Put him in against some right-handed pitchers that he’s had good success against when he starts swinging the bat like he’s capable of.”

What happened with that swing?

“Believe me I do not have an answer for that,” Collins said. “I really don’t. Jason does not have an answer for that because he feels fine.”

Enter Valdespin and Baxter, for starters. Collins said Tuesday night, when he announced the Bay part-time plan, his lefty hitters deserved a crack based on their bodies of work this season.

“I’m excited to play,” Baxter said. “Any time you step on the field is an opportunity and that’s kind of the way I was looking at it this season.”

Baxter, who went 0-for-4 last night, has struggled since his July 30 return from the disabled list, going 1-for-12.

Valdespin, though a natural infielder (second baseman by trade), is also part of the mix in his fourth rookie call-up with the team this season.

“There’s no pressure on me,” said Valdespin, who was 1-for-3 with his seventh double of the season, and also walked. “This is the game, and you play hard. That’s all you can continue to do. It’s all I’m going to do.

“Nothing is easy in this game. Everything is hard. All you can do is practice, practice because you want to do everything good.”

Baxter, an Archbishop Molloy High School product, was hitting .323 as a part-timer when he made the catch that etched him forever in Mets’ lore. But when he robbed Yadier Molina and preserved Johan Santana’s no-hitter June 1 against the Cardinals, he crashed into the wall. Two days later, he was placed on the disabled list with a displaced right collarbone and fractured rib cartilage next to his sternum.

“It’s been really tough for him, but the best thing he’s done was he approached the rehab the way I think he should approach it,” said Collins, noting Baxter had 49 at-bats in his rehab stint before rejoining the team. “He came up here feeling good about himself offensively. But he was playing so well when he got hurt, he was swinging so well. … It would have to be almost a go out there every day to get back to where he was.”

Collins was quick to point to Baxter drawing a franchise record five walks in a single game in San Diego during the recent trip.

“He’s seeing the ball good,” Collins said. “He’s going to start playing against righties, which we’ve got some coming up, so hopefully he regains that stroke he had when he got hurt.”

Valdespin, who has set his own franchise record with five pinch-hit home runs, is being asked to transfer his talents to the outfield. Collins put him in left last night because it is a bit easier to play than right field for a novice.

“All I can do is continue to come to the field every day and work on everything to be perfect,” Valdespin said. “Nobody is perfect in this game, but we all try to be. That’s what I try to do every day.”